As a result of traditional selective breeding methods, milk production in dairy cows far exceeds the requirements of the newborn calf. Because of udder size, position, and anatomic configuration for rapid removal of large volumes of milk, the mammary glands of dairy cows are especially prone to injury and infection. In particular, mastitis, an infection of the mammary gland, is common in milking dairy cows.
Clinically, mastitis typically produces heat, swelling, tenderness and possible deformation of the udder. Although the milk from a mastitic udder is generally safe for human consumption, a major concern is the cost to producers. Mastitis causes a decrease in the amount and quality of milk produced by the infected cow. With decreased quality, the price obtained for the milk likewise decreases. Mastitis is typically caused by bacteria which enter the teat through the teat orifice. These bacteria account for about 90 percent of all udder infections.
More than 80 species of microorganisms have been identified as causal agents, although approximately 95% of mastitis is caused by four pathogens; Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysagalactiae, and Streptococcus uberis. Mastitis causing pathogens fall into two categories, namely contagious and environmental. Contagious bacteria, such as Streptococcus agalactiae and Staphylococcus aureus, primarily colonize host tissue sites such as mammary glands, teat canals, teat skin lesions etc. and are spread from one infected cow to another during the milking process. The mastitis causing bacteria can be spread among cows by contaminated milking units or machines, by cow to cow contact, or can be transferred by milking personnel having contaminated hands. Environmental bacteria, often streptococci, enterococci and coliform organisms, are commonly present within the cow's surroundings from sources such as cow feces, soil, plant material, bedding or water, and infect by casual opportunistic contact with an animal during the inter-milking period. General housing conditions, such as stall size, ventilation, bedding material, and access to pasture are also known to have an impact on mastitis spread.
Typically after milking, a drop of milk remains on the tip of the teat, which can serve as a center for bacterial growth. Also, the teat canal is relaxed or dilated from the vacuum applied by the milking machine. The bacteria can then migrate through the teat orifice and into the internal teat cistern to cause inflammation and blockages.
Systemic and local antibiotic administration is a proven method of mastitis treatment and prevention. Intramammary administration of antibiotics during non-lactating periods, known as dry cow therapy, is an established method for mastitis prevention when a cow is not lactating. For cows that are lactating, teat dips have long been used as a preventative for mastitis. Post milking teat dipping is considered to be the single most important factor in mastitis prevention. Teat dips can function by providing a physical barrier to bacterial entry through the teat orifice. Additionally, bacteria that may be present can be killed by antibacterial ingredients of some teat dips. Typically, the procedure of applying teat dip includes filling a cup or other suitable container with the dip formulation and dipping the teat therein.
The dip formulation can be purchased either as a liquid concentrate or in ready to use form. Ready to use forms include aerosol or other spray forms. Generally, the liquid concentrated antibacterial is supplied in a 1 gallon jug or bottle. The dairy farmer must dilute the antibacterial concentrate, typically in tap water, to obtain the correct dilution prior to administering the treatment to the animals. It is important to achieve the correct level of antibacterial ingredients per unit volume. Generally, the antibacterial is diluted with water at a ratio of about 1 to 5 ounces of concentrate per gallon of water or other aqueous solution to form the treatment solution. Too concentrated of a solution may cause irritation to the skin of the animals, including dryness, cracking, and chafing, and could create additional health problems. Too weak of a solution may be ineffective for destruction of the bacteria.
To prepare the solution for use, a volume of concentrate is poured from the bottle or container and then added to a volume of diluent, typically tap water. Often the measuring and mixing methods used by the farmers are inaccurate. Typically, the concentrate is poured into a measuring cup or other device before being added to a pre-measured volume of water. However, often random amounts of concentrate are mixed with random amounts of water in proportions that result in a substantial excess or an insubstantial amount of active materials. The resulting diluted treatment solutions are often ineffective in treating or preventing mastitis or may even cause additional health problems, irritation, for the animal if used in excess. A simple method of measuring and dispensing a precise, pre-determine volume of concentrate from a container for dilution into another container is needed in this art.
Valves, taps, spigots, and many other devices for dispensing liquid from containers are well known in the art. However, the majority of these devices are not capable of dispensing a pre-determined or measured volume of liquid material. Further, these devices often drip and leak. Attempts have been made to provide devices that measure and dispense set volumes of materials; see for example, U.S. Pat. Nos. 1,969,110 to Teach; 2,220,605 to Kreisberg; 2,518,520 to Broun; and 5,694,794 to Jerg, et al.